On your 2019 f1116, you did check that line 21 is greater than line 14 to accommodate the carryback. The IRS instructions only call for a "revised f1116" for 2019. I take that to mean , the revised is the same as the original except that you would insert into the f1116 worksheet the amount of the carryback on line 10 of the worksheet.
That will be added to the original amount of foreign tax paid and summed up on line 14, the total available for credit. The end result is to increase your foreign tax credit for 2019.
